This applicaton claims priority from U.S. Provisional Application No. 60/161,584 filed Oct. 26, 1999, which is incorporated herein by reference.
The present invention relates to a suturing instrument. The purpose of suturing is to connect two surfaces or layers of substrate by means of a thread, line, cable, or wire which is repeatedly inserted and withdrawn alternately in each layer or surface. This is done in order to connect at least two layers or surfaces in direct opposition to each other in order to 1) fuse the layers or surfaces into one unit, 2) close a surgical incision or wounded biological tissue, or 3) produce a watertight or airtight vessel.
There are two primary applications for suturing. The first is medical and biological, for surgical repairing or closing wounds and incisions in living tissue. The second is commercial and industrial applications for connecting or sewing together fabrics or sheets of various materials such as textiles, clothing, sails, sport equipment, or binding of paper products. The suture material must be a long flexible substance with enough tensile strength to hold layers together, and includes string, wire, cable, protein (hair), natural fibers, or a synthetic polymer such as nylon or vicryl. The suture material can be permanent, temporary (to hold substrates together for a short duration or until another connecting method is applied such as glue or welding), or absorbable. Absorbable suture material is typically used for biological applications, with the suture eventually broken down and dissolved in living tissue after a wound has healed.
The material being sutured is the substrate, and usually consists of opposing surfaces to be brought together, typically in direct contact. These opposing surfaces can be composed of one substance, or different substances. Commercial substrates usually consist of layers of materials such as rubber, paper, cloth, or other textiles. Medical and biological substrates are usually composed of wounds or incisions in skin, muscle, fascia, or internal organs.
Ancient suture methods are still the most common type, typically requiring basic needle and suture materials. Suture alone is too flexible to penetrate substrates, so it is typically attached to a rigid penetration device with a sharpened end, such as a needle, spike, lance, or harpoon. Usually, the needle is alternately inserted into one surface of the substrate by penetration, and pulled out from a nearby site. This is repeated on the opposite surface of the substrate, and when the suture is pulled taut, the two surfaces are brought together into immediate proximity or contact. The degree of tension applied to the suture determines how tightly the substrates are held together. Placing a single suture through two or more substrate layers or surfaces completes a single xe2x80x9csuture cyclexe2x80x9d with the result being a xe2x80x9cstitchxe2x80x9d.
In general, multiple adjacent sutures were placed in a linear fashion by repeating the basic suture cycle, typically resulting in a line of adjacent, evenly spaced stitches. The result is a xe2x80x9csuture linexe2x80x9d.
Several suturing devices have been developed to operate suture cycles. Manual devices are composed of needle and thread which are placed by simple hand dexterity. Clamps and needle drivers have been developed to allow manual driving of needles through resistant substrates that would be difficult or impossible to penetrate using hand dexterity. Finally, automated sewing machines typically use two or more threads and an automated needle penetration and entanglement device to rapidly and automatically develop a suture line.
Current suturing technology will be illustrated by medical suturing; the same basic principles apply to commercial and industrial suturing. This technology is designed to join tissue surfaces to close wounds or incisions, or stop bleeding. Less commonly, medical suturing is used to place a line into a tissue plane for retraction to gain greater access to a surgical field. The following medical suture types are routinely used:
Interrupted sutures are composed of single separated stitches, which are typically placed at even intervals along an incision.
Continuous sutures are achieved by placement of a single stitch at one end of an incision, and then repeating the suturing cycle sequentially along the incision to the opposite end. This is also called a xe2x80x9crunning stitchxe2x80x9d.
Continuous and locked sutures are the same as continuous sutures, but with the needle and suture material occasionally passed under the previous stitch before continuing to the next suture cycle.
Purse string sutures are used primarily to close circular or cylindrical defects. A knot is tied at one end of a suture, and using a curved needle the other end of the suture is passed in a circular manner around the bottom of the incision towards the starting point, then continued in an upward spiral toward the top of the incision. Once the surface is reached, the suture is pulled tight which closes the circular defect in a xe2x80x9cpurse-stringxe2x80x9d type manner.
Figure eight sutures consists of two suture cycles crossed over each other in an xe2x80x9cXxe2x80x9d pattern.
The current suture cycle technique used for nearly all surgical applications consists of several steps:
1. Obtain suture and attached needle, usually from a sterile package.
2. Clamp a needle driver onto the midportion of the needle.
3. Manually use the needle driver to push the needle into the tissue surface on one side of the incision.
4. Push and/or rotate the needle through the tissue with the needle driver until the tip of the needle emerges from the tissue surface nearby.
5. Unclamp the needle driver from the midpoint of the needle, move the needle driver to the emerging needle tip, and reclamp the needle tip with the needle driver.
6. Pull and/or rotate the needle from the tissue surface with the driver, then continue to pull until the entire length of the needle emerges from the tissue. This leaves the suture in the tissue along the needle track.
7. Pull the suture through a short distance.
8. Regrasp the needle at the midpoint with the needle driver.
9. Push the needle through the tissue surface on the opposite side of the incision, push and/or rotate the needle through the site until the tip of the needle emerges from the tissue surface nearby.
10. Unclamp the needle driver from the needle midpoint, move it to the needle tip, and reclamp the needle tip with the driver. Pull and/or rotate the needle from the tissue surface with the needle driver until the entire length of needle emerges from the tissue.
11. Pull the suture through the opposite tissue surface.
These steps complete the basic suture cycle, and all surgical suturing techniques are built from the components of this cycle. Note that the needle handling instrument (needle driver or clamp) must be unclamped from the needle, then reclamped onto the needle multiple times to complete a single stitch cycle. This is currently the primary method of placement of sutures used worldwide, with the disadvantages of being labor intensive and tedious, requiring multiple repetitions of the stitch cycle progressing down the length of the incision.
After an interrupted suture is placed, the suture is pulled taut and tied (usually with square knots). If a continuous suture is to be placed, multiple repeats of the basic cycle are done until the entire length of the incision is covered. Then the suture is pulled taut and tied. Each suture cycle is called a xe2x80x9cthrowxe2x80x9d and each throw results in placement of one stitch. If continuous and locked sutures are to be placed, the free suture is passed under the previous loop formed by the previous stitch before the next suture cycle is initiated. A figure eight suture is essentially two xe2x80x9ccrossed overxe2x80x9d throws.
Suture cycles are tedious multistep procedures which are time intensive. They require relatively intensive labor and result in a relatively slow closure of incisions or wounds. A more efficient method of placing sutures would save time and labor, and would reduce the total operating room time and anesthesia time, allowing scheduling of more cases in a fixed period of time such as an operating room (O.R.) shift.
Several suturing devices involving helical-shaped needles are known. U.S. Pat. Nos. 5,356,424 (Buzerak et al.) and U.S. Pat. No. 5,562,685 (Mollenauer et al.) disclose laparoscopic suturing devices with a helically-wound front-end portion with a needle point. Some of the disadvantages of these devices include the necessity of using multiple cannulas for introducing additional surgical instruments such as forceps, cutting instruments and light sources. In some embodiments of the Buzerak et al. device the helical needle is removed from its handle in order to tie the suture. In another embodiment, the helical needle is hollow and contains suture material, but there is nothing to keep the suture material secure at the needle tip while the needle is rotated into the tissue.
U.S. Pat. No. 5,330,503 (Yoon) discloses spiral and helical-shaped absorbable suture needles. The needles have barbs and a locking device to prevent their movement after they are placed in the tissue. The needles are designed to be used without suture material.
U.S. Pat. No. 5,545,148 (Wurster) discloses an endoscopic suturing device which uses a separate helical-shaped needle with a suture attached to the blunt end. The device utilizes two rods to manipulate the needle.
A first embodiment of the invention is a suturing instrument comprising first and second members. The first member comprises a first helical portion and a second straight portion, the helical portion having a configuration including at least one complete revolution of a helix. The first member has a means for attaching a suture. The helix has a central axis and a sharpened tip.
The second member comprises a straight hollow member having an interior lumen extending from a first open end to a second open end. The straight portion of the first member is attached to the first end of the second member such that the second member is disposed within the helical portion of the first member along the central axis of the helix. The second end of the second member extends toward the sharpened tip of the first member.
A second embodiment of the suturing instrument comprises first and second members and a connecting member. The first and second members each have a first helical portion and a second straight portion. The helical portions each have a configuration including at least one complete revolution of a helix. The helices each have a central axis and a sharpened tip.
The first and second members each comprise a means for attaching a suture. The straight portions of the first and second members are attached to the connecting member such that the first and second members are disposed side by side, with parallel central axes.
A third embodiment of the suturing device comprises at least a first member and a handle, the member having a first helical portion and a second straight portion. The helical portion has a configuration including at least one complete revolution of a helix. The helix has a central axis and a sharpened tip. The member has a means for attaching a suture. The handle has first and second sections connected by a universal joint. The handle is attached to the straight portion of the member.
A fourth embodiment of the suturing device comprises first and second members and a means for simultaneously rotating the first and second members. The first and second members each have a first helical portion and a second straight portion, the helical portions having a configuration including at least one complete revolution of a helix. Each helix has a central axis and a sharpened tip. The first and second members each have a means for attaching a suture. The straight portions of the first and second members are attached to the means for simultaneously rotating the first and second members.
A fifth embodiment of the invention is a method for suturing a tissue comprising introducing a suturing instrument into the tissue, rotating the instrument in a first direction into the tissue, creating a path for the suture, rotating the instrument in a second direction out of the tissue, wherein the suture is deposited along the path.
A sixth embodiment of the invention is a method for loading a suture into a helical suturing instrument. The method comprises the steps of attaching a length of suture material to an end fitting, placing the end fitting with attached suture into one end of the hollow member, and moving the end fitting through the hollow member from one end to the other end. The end fitting deposits the suture material along the length of the hollow member.